Merge pull request #106 from ahmadia/core_run_job_doc_fixes

small documentation fixes
Merge pull request #107 from ahmadia/fix_build_profile_test_general

generalized readlink location
use absolute paths for temporary directories

This works around an OS X.8 issue where os.path.realpath(d) resolves to
a different dir than d when d = tempfile.mkdtemp()

This PR supersedes #105 and #108